Accumulator.



(No Model.)

H. LEITNER.

ACCUMULATUB.

(Application filed Mar. 25, 189B.)

Patented Mar. I3., |900.

2 Sheets-Sheet I.

N- 645,478- Patented Mar. I3, |900.

* H. LEITNER.

ACCUMULATOR. (Applicstiog led 15111.17.` 25, 1898.)

2 sheets-sheet 2.

(No Model.)

Tric f:

PATENT HENRY LEITNER, OF LONDON, ENGLAND, ASSIGNOR TO THE ELECTRICALUNDERTAKINGS, LIMITED, OF SAME PLACE.

ACCUMULATOR.

SPECIFICATION forming part of Letters Patent No. 645,478, dated March13, 1900. Application filed MarchV 25, 1898. Serial No. 675,203. (Nomodel.)

To all whom, it may concern:

Beit known that I, HENRY LEITNER, eleotrical en gineer,a subj ect of theQueen ofGreat Britain and Ireland, residing at 207 Piccadilly, London,W., England, have invented certain new and useful Improvements in theConstruction of Accumulators, of which the following is a specification.

This invention relates to improvements in connection with theconstruction of accumulators or secondary batteries, and has for itsobject to provide an accumulator which will be more durable and lesslikely to get out of order than those hitherto employed, with also thespecial advantage ofinsuring perfect contact between the active materialof the plates and the carriers under all conditions of charge anddischarge and expansion and contraction.

The main feature of my invention consists in the utilization in apeculiar manner of the pressure produced by the expansion of the peroxidplates, so as to insure that the parts be kept in proper position and toprevent the lead peroXid from dropping out of the plates, thearrangement also insuring a larger contact-surface.

In order that the invention may be more clearly understood, reference ishad to the accompanying drawings, in which- Figure l is a plan of anaccumulator constructed according to my invention. Fig. 2 is a verticalsection of the same, taken between two of the plates. Figs. 3 and 4c arerespectively an elevation and a cross-section of grids for the peroxidplate. Fig. 5 shows a modied form of plate, and Figs. 6 and 7 arerespectively a plan and a vertical section of the arrangement as appliedto zinc accumulators. Fig. 8 is a detail View.

The peroxid plate I prefer to employ is formed as follows: A double gridor frame A is used, consisting of two lead sheets of suitableproportions provided with contact bars or extensions a at one side. Eachof these plates is formed with a series of holes ct,which may behexagonal 'in shape. These are stamped from .the plate by conical dies,so that the sides of each hole are beveled. The hole is thus slightlylarger at one side than at the other, as shown in Fig. a. Two suchplates are taken, and after they have been iilled with the paste orAmaterial from which the peroxid is to be formed they are placed face toface,

v so that the larger sides of the holes are at the inside. f The platesare also'arranged so that the holes do not register with each other, thebars of one plate crossing the holes of the other. Owing to the beveledform'of the holes, the plugs of paste will not be liable to fallout evenwithout the pressure produced in the manner hereinafter described'. As,however, the arrangement' hereinafter described prevents the peroXidfalling from the plate witho'ut such construction, I may employ the formof plate shown in Fig. 5. This consists of a single grid A perforated toreceive the paste. The rim a2 is thicker than the body ofthe plate, andthe paste fills up the vplate to the level of the rim, as shown in thedrawings. On both sides of the negative plates parallel pieces B ofresilient material, such as cellu loid, are fixed. These bars are notsecured directly to the plate, but to the inclosing frame hereinafterdescribed. Three of these bars are preferablylemployed in plates ofordinary size; but a larger number may be used.

These separating-pieces, which are used to transmit the pressure and notmerely as distance-pieces, I may make of triangular shape incross-section, and they may also be hollow.

This form allows the sides of the pieces to bulge out on transversepressure being applied to press the plates together. As the material iselastic, any compression which may occur will not permanently change theshape of the bars, but these will spring back again into their normalshape on the pressure being relieved. A series of plates are placedtogether, the faces of the positive plates resting against theseparating rods or tubes ot' the negative, as shown clearly in Fig. l.The plates when inserted in the case C rest on the supportingbars b,which may be of the same material as the separatingbars. Onboth sides ofthe series or block of plates so formed a plate D of impregnated Wood orothersuitable material is placed.l This is preferably grooved at one,two, or more parts, and in the grooves bands E of theresilient'insulating material, as Celluloid, above described, aretightly fitted. These bands are continuous IOO and of considerable widthto give the required strength and great resistance to a pulling force.Nhen the arrangement is complete, a solid mass is formed, the platesbeing pressed closely together, separated only by the elastic tubes -orbars.

The resilient casinginclosing the plate consists of a bar or rim F ofthe same material as the resilient bars,extending completely around theplate and covering part of the lug. On this rim the perforated'sheets f,also of lthe said resilient material, are iixed, so that the plate iscompletely inclosed. The celluloid is not ijxed to the lead plate at anypoint, but merely incloses it. The perforations of these sheets do notextend close to the edges, so that side strips of unperforated materialare formed which cover the sides of the lead grids and protect them fromthe action ofthe electrolyte. These rims are shown of squarecross-section in Fig. it; but any other suitable cross-section may beemployed. The bars B, which in the detail views are rectangular incross-section, are fixed at their ends only to the unperforated edges ofthe sheets f, the

main part of these bars being quite clear of the perforated sheets. Anyextension in length of the plate will thus stretch the bars, which willreturn the plates to their proper shape when contraction of the peroxidoccurs. A cross-strip f may also be employed,

anyside expansions. As the conducting-lug, as Well as the sides of thegrid, is protected by the frame from the solution, it will not be liableto get attacked. inclosing frame or case I prefer to employ only inconnection with the negative plate. The positive plate may be leftunprotected and simply supported by the side band and by side strips andsmall supporting-pieces, which prevent the positive plates dropping orshifting -with respect to the negative.

The material of the bands and bars should possess considerable strengthand stretch .very little for a large pull, so that the amount ofexpansion .which occurs in the accumulator will cause a very powerfulreaction, which presses the halves of the plates tightly together, andtherefore the plugs in the grids hard up against theirconducting-surfaces.

tendency will be to cause the two sheets or perforated plates of lead ofwhicheach plate is built up to separate, this action taking place owingto the beveled form of the holes and the fact that the plates are placedback to back and are joined together at the edges only. Each plate willthus tend to bulge slightly out on both sides, so as to become expansionis resisted by the outer bands and the separating-pieces, and as theseare all resilient they will give slightly to the great pressure producedby the expansion. The expansion owing to this back pressure will thusThis arrangement of cause the peroxid plugs to be'pressed -irmly againstthe lead grids, giving the largest possible conducting-surface. As theperoxid contracts, instead of the pressure beingat once taken oft, aswould be the case if the parts were not resilient, the extension orcompression of these resilient parts is utilized to recompress theplates until they return to their former size. The plates are thus againpressed quite flat, and the active material in both plates is still kepttightly against the grid. The peculiar formation of the grids enablesthis action to take place, as the expansion does not tend so much toopen the holes, and thus to be transmitted'sidewise,

but only slightly separates the two plates v against the force of thebinding material of the whole block. Inthe single-plates the action issimilar, with the exception that the peroxid is not inclosed between twogrids, `but only by the external casing.

This arrangement also allows a large number of thin plates to beemployed instead of a smaller number of thick ones, as in the presentconstruction ot' accumulators. A greater surface is thus provided, whichsubstantially ini creases the efficiency of the accumulator. At

the same time the block of plates formed in y the manner described isquite solid and will g not be injured by rough usage whether me- 5chanical or electrical.

iixed only at its ends and serving to take up As applied to zincaccumulators, Figs. 6 and Y 7, sufficient space is left between theseparating-pieces to allow of thezinc plates G being inserted. Thesezinc plates are constructed so that they are quite free from pressure,being held in parts by means of insulatingpieces B, which do not,however, bear upon the zinc. These plates are formed with cores g ofcelluloid or like material,-Fig. 8, which extend a little beyond thelends of the lead on which the zinc is deposited. The lead base partlysurrounds-these plates of celluloid, so as to form a sheath, leaving,however, projecting portions. The corners of the core which are outsidethe sheath are provided with small blocks g' of celluloid orotherinsulating material, which serve as distancepieces. W'hen theseplates are dropped in between the peroxid plates, these distancepiecesbear against those plates and keep the When the peroxid in the platesexpands, its

zinc entirely clear of any contact. There is thus no danger of zincbeing deposited from l The central separating-pieces B' bear againstthicker and to increase the width of the block of plates formed as abovedescribed. This In the spethis part on each side and assist in holdingthe zinc plate.

What I claim as my invention, and desire to secure by Letters Patent, is

l. In accumulators, the combination with peroxid plates,separating-pieces of highlyelastic material placed between the said IOJIIO

plates, and encircling parts encircling the plates and binding themfirmly together, of zinc plates having a core of insulating material anddistance-pieces or blocks carried by the said core and clear of thezinc, the zinc plates being placed between the resilientseparating-pieces, substantially as described and for the purposesspecified.

2. In accumnlators the combination with peroxid plates adapted to expandtransversely, separating-bars of highly-elastic material placed betweenthe said plates, and bands of elastic material uniting the platestogether, of zinc plates having a core of celluloid and distance-piecesor blocks carried by the said core and clear of the zinc, the zincplates being placed between the resilient separating-bars, substantiallyas described and for the purposes specified.

3. In accumulators the combination with peroxid plates formed from twogrids and adapted to expand transversely, separatingbars of resilientmaterial placed between the said plates, and bands or binding parts alsoof resilient material inclosing the plates, zinc plates having a core ofinsulating material extending completely across lthe same, leaving aclear portion of the core at the center, and separating-blocks ordistance-pieces f1tted to the projecting parts of the core, the zincplates being held between the peroxid plates substantially as described.

4. In accumulators of the kind described, peroxid plates having aresilient case formed by a rim of resilient material surrounding theplates, perforated sheets of the same material fixed on the rim at eachside and inclosing the plate and resilient bars attached at each end tothe frame, the whole forming a resilient case adapted to take up anyside expansion of the plate and to return the plate toits normal shapeon the contraction taking place, substantially as and for the purposesspecified.

5. In accumulators the combination of negative peroxid plates, having aresilient case formed by a rim of resilient material surrounding theedges of the plates and protecting the contact, perforated sheets havingan unperforated rim covering the edges of the lead grids and fixed tothe rim, and resilient bars on both sides of the said plates fixed attheir ends only to the case, with positive plates placed between thenegative and separated bythe resilient bars and bands of resilientmaterial binding the block of plates together, substantially asdescribed and shown and for the purposes specified.

In witness whereof I have set my hand in the presence of two witnesses.

y HENRY LEITNER. In presence of- EDwARD P. MACLEAN, HENRY W. MARTIN.

